Narrator: It lives in the world's imagination as much as it does in reality: California-- the Golden State.

But the truth is: this land of dreams sits in one of the most biologically diverse places on Earth.

♪ [Rattling] ♪ Can wildlife and 40 million people coexist... even thrive together?

[Waves crashing] In California, the question is urgent.

Next door to some of the world's most exclusive real estate are extraordinary neighbors... ♪ who we are only beginning to understand and care for.

They are the true stars of Planet California... and they are ready for their close-up.

♪ ♪ For eons, California developed in isolation... ♪ an island created by great mountains that hemmed in the north... ♪ south and east... ♪ and to the west... the sea.

♪ From Pacific beaches to the high reaches of the Sierra Nevada range, the extraordinary variety of landscapes fostered myriad endemic species.

♪ As people poured in, wildlife was pushed out but not everywhere... High in the White Mountains, the bristlecone pines remained untouched.

The one called Methuselah took root more than 4,500 years ago, making it one of the oldest organisms on Earth.

♪ A stubborn survivor in the face of epic change: earthquake, fire, flood, drought... the tree shuts down all of its systems and waits out harsh conditions.

♪ When left alone, nature usually finds a way... a concept being tested in California.

♪ [Birds calling, waves crashing] Off the iconic Big Sur shoreline, a deep-sea dweller bears proof.

♪ The blue whale: the largest animal to ever live.

♪ [Expels air] ♪ 30 years ago, commercial whaling had culled 99% of these magnificent creatures, so the recent appearance of a pod just a few miles offshore is astonishing.

♪ [Expels air] The rarest of sightings: mother and calf.

These two are in the vanguard of a new generation that has never known whaling.

♪ Left alone, their numbers are slowly rebounding along America's west coast.

♪ The line of foam reflects the seabed below: 2 water masses run side by side, one along the jutting continental shelf, the other over the abyss.

♪ When the winds are right, upwellings of nutrients from the deep foster a close encounter between the titanic and tiny... ♪ blue whales and krill.

♪ Krill rise up from the edge of a world long out of our reach.

Some of the continent's deepest canyons and most spectacular mountains-- just south of San Francisco-- all of it underwater.

The acclaimed Monterey Bay Aquarium Research Institute studies this submerged terrain with remote vehicles, pushing our understanding of the outer edges of life on Earth.

[Man speaking indistinctly] Nearly a mile down, the ROV enters an everlasting night.

♪ Researchers record species and habitats-- tracking changes, not making them.

♪ It's a radically different first encounter from California's early explorers.

♪ Sponges and corals colonize canyon walls-- a deep sea habitat that, because of its inaccessibility, has seldom been glimpsed till now.

♪ Down here, where the sun never shines, about 90% of animals make their own light.

♪ Californians don't have to go to extremes to meet their aquatic neighbors.

A walk to the beach will do.

[Waves crashing] On early summer nights, bioluminescent algae can swarm in the millions, turning the waves a radiant blue.

And on a few extraordinary nights, on particular beaches, there's dancing in the moonlight.

♪ Riding the high tide, thousands of grunion-- a California native-- come ashore to mate.

♪ The female burrows in and waits for a male to cozy up and fertilize her eggs.

♪ A guitarfish pops out of the water as well, grabbing a quick bite at the amorous event.

♪ Beyond the surf line, another mating frenzy reveals the secret of sustainable fishing.

♪ The tentacles of excited male squid flash red and iridescent green as they clasp their mates.

♪ The females deposit eggs on the shallow sea floor in seemingly inexhaustible abundance.

♪ Calamari is California's most productive fishery thanks to responsible fishing and a prolific reproduction rate.

The entire population replaces itself annually.

♪ But heading down the Pacific Coast Highway, another resurgent species is a reminder of unintended consequences.

[Vocalizing] Elephant seals are deep divers, who spend most of their lives far out to sea.

[Sea gulls crying] They break that habit to give birth, molt, and mate.

To beat the heat, they bury themselves in cool sand.

[Grunting] While cows sunbathe, bulls throw their considerable weight around.

They vie for supremacy and the right to breed.

The alpha male dispatches his challengers quickly.

♪ The losers take out their frustrations by trying to mate with young pups.

[Pup crying] ♪ It's perilous to be a youngster.

Better to stay out of the way.

These pups are teaching themselves how to swim in a shallow and ephemeral freshwater creek, a curious adaptation for one of the ocean's deepest-diving animals.

[Vocalizing] The dramatic scene on the beach draws hundreds of thousands of tourists annually.

Just steps away from a parking lot, they can watch a spectacle that a century ago had nearly vanished from the world.

Hunted for their blubber, like the blue whale, only 100 were left.

Now, with complete protection, the population in California has risen to nearly 150,000... which has led to another resurgence.

♪ Seals are the favorite prey of great white sharks whose numbers are also growing.

♪ [Vocalizing] ♪ Big waves and great whites.

Both are found near San Francisco at Mavericks.

[Surf music playing] The legendary surf spot lies in the Red Triangle-- the largest concentration of white sharks in the north Pacific, but that doesn't deter the world's most daring surfers.

Ryan Seelbach has been riding Mavericks for 20 years.

As a geologist, he understands what makes this place special.

♪ Seelbach: Mavericks is really big and bigger than a lot of the other waves here along the coast, primarily because of the geology.

It hits a shallow rock or a shelf and explodes over that shelf.

Narrator: An adventure athlete, Seelbach relishes what nature puts in his path.

Seelbach: Surfing Mavericks, there's a ton of trial and error, you know, trying to paddle for waves and you don't get 'em.

And I think we paddle for probably a lot more waves than we get to ride.

Narrator: The giants can reach as high as a 6-story building.

[Surf music playing] ♪ Seelbach: When that wave breaks, you just--you feel it.

Your whole body bounces.

♪ Narrator: The water is frigid, about 50 degrees Fahrenheit.

A mistake can mean serious injury.

Seelbach: At Mavericks, you got these giant mountains, this cliff, these rocks, and you're about a half-mile out to sea, and you get put in these situations where you just feel like you just gotta be able to save yourself.

[Surf music playing] ♪ Narrator: A close encounter not for the faint of heart.

♪ [Ocean rushing] 300 miles downcoast, in the Santa Barbara Basin, warm currents from the south clash with the California Current-- a cold-water "river in the sea" that comes from the north.

It's a potent mix, sparking a burst of life seldom seen so close to shore.

[Whale singing] A great shoal of fish rises.

♪ Dolphins know how to read the signs when the event is underway.

[Sea gulls crying] ♪ Seabirds answer the dinner gong, too.

[Sea gulls crying] Anchovies and sardines feed in the upper layers of the California Current, where sunlight triggers plankton blooms and fires up the food chain.

♪ The massive shoal is both a shield and magnet, guarding the fish and attracting hunters simultaneously.

♪ The little fish crowd together, attacked from below and above.

♪ Crafty California sea lions push the panicked fish back together, picking off strays as they go.

♪ Lunging through the middle, mouth wide open, the humpback whale isn't so delicate, swallowing tons of fish in a single gulp.

♪ [Expels air] ♪ [Whale vocalizing] [Expels air] In minutes, the bait ball vanishes, leaving only scales behind.

♪ The survivors of the slaughter scatter to nearby stands of giant kelp in the Channel Islands National Marine Sanctuary, home to countless billions of animals and a conservation success story.

♪ Topping out at more than 500 pounds and living up to 75 years, the giant sea bass was prized by sport and commercial fishermen alike.

By 1982, it had become so scarce, many scientists feared it had disappeared altogether.

40 years later, with protective laws and protected habitat, the emergence of a young school in the kelp forest spawns new hope.

♪ The giant sea bass avoids the California sea lions that make the forest their playground.

♪ The sea lions can't resist breaking up the bass party.

♪ They chase the fish into the canopy, not to eat them but simply for the sport of it.

♪ Restoring ecosystems allows all to thrive... ♪ from the waving arms of the brittle starfish to the California sheephead, which knows a little about transformation.

♪ The immature fish is yellow.

As she grows, she turns a dull pink.

And when she's half-grown, she transitions to the black head and tail showing that she is now a he, ready to claim and defend a breeding range.

♪ The striking orange color of California's official state fish--the garibaldi-- should make it a target for predators, but nobody pushes these flashy characters around.

♪ Fiercely territorial, the males prepare and maintain the algal nest for their offspring.

Like an obsessive gardener, he fusses over the vegetation, nibbling it to an exact height.

He fans the bright yellow eggs, aerating them with oxygen.

When an egg-eating sea urchin wanders onto the nest, the protective father unceremoniously shows it the way out.

♪ Kelp keeps a tenuous hold on the ocean bottom.

♪ Dislodged during storms and growing weaker with age, the entire plant lifts off the sea floor.

But when it lands on the beach, we find it smelly and unattractive.

Still, loaded with small crustaceans and sea worms, it's really a gift from the sea.

[Birds chirping] The size of a sparrow, the Western snowy plover lays her eggs in a tiny depression directly on the sandy shore.

Well camouflaged, it hides in plain sight.

♪ It's a strategy honed over millennia that's proven problematic since all the new neighbors moved in.

♪ [Plovers chirping] This snowy plover makes a different choice.

Rearing a chick in the dune plants on the high ground seems less vulnerable than putting it directly on the beaten path.

The father does the lion's share of parenting, but the chick is a scrappy mite that can fend for itself.

No bigger than a cotton ball, it starts foraging when just a few hours old.

[Chirping] Close to the seaweed, the plover chick on the beach has a tasty advantage over the chick on the hill.

♪ In less than a month, the chick will fledge and fly.

Getting to that stage is the trick.

♪ The crow is an unwelcome stranger and new threat in these parts.

It followed people here, scavenging their trash.

[Spaghetti Western music playing] ♪ The high ground turns out to be less safe than supposed.

♪ [Squawks] Between keen-eyed hunters... [Cawing] and the people who don't see them at all, plovers have been pushed to the brink.

Often, humans seem blissfully unaware that their ocean paradise is, in fact, a wilderness.

♪ Long before Santa Barbara became a popular surf spot, it attracted hundreds of lusty leopard sharks.

♪ Leopard sharks don't attack people.

Ignoring the beachgoers, they scan the sandy bottom for food and look for mates.

♪ They're year-round residents, unlike the great whites.

♪ Adolescent white sharks just visit.

♪ Surfers aren't seals, though from underneath, their boards may bear a resemblance.

♪ California protected great whites in 1994, when their numbers had plummeted.

♪ The appearance of these juveniles is a sign that it's working, if perhaps alarming to the people who share the water.

♪ This one heads south, seeking better hunting.

[Country music playing] The coyote is one animal that has truly benefited from the human invasion.

♪ We've cleared out many predators and created new food sources for the wily dogs.

[Screech] ♪ [Coyote howling] ♪ [Cawing] Meanwhile, its original home, the dry grasslands, is virtually people-free.

[Coyote howling] Years of drought made a place that was always tenuous untenable.

The Carrizo Plain is the last remnant of a grassland that once stretched hundreds of miles through the center of California.

After a tough go of it, farmers have left it to the wild things.

♪ With temperatures regularly rising into the triple digits, most animals head underground to a vast network of tunnels-- the original Hotel California.

♪ [Rattling] ♪ When the sun is low, irrepressible kit foxes pop out to play.

♪ No longer threatened by plows and pesticides, they may yet reclaim their home.

♪ There's plenty of competition for the endemic San Joaquin antelope squirrel.

[Rattling] [Hissing] ♪ The kit fox father scours the expanse for food for his pups.

♪ ♪ With only 7,000 kit foxes left in the world, his mission is critical.

♪ The father will need to find more to keep them all satisfied.

♪ The rattlesnake is an ambush hunter.

It waits for its toxin to work before consuming the paralyzed rodent.

[Fly buzzing] ♪ Dry conditions benefit some creatures.

Grasshoppers love a good drought.

They're a staple food for many of the residents in the Carrizo grassland.

One grasshopper makes a full meal for an adult burrowing owl... but not enough to share with his chicks.

Having fortified himself, he brings them a spider.

Below the surface, something is happening.

The tunnel dwellers sense it first.

[Rumbling] Soon, the tremors rattle even the elk.

[Rumbling] [Louder rumbling] ♪ Every year, Planet California experiences some 10,000 earthquakes along the San Andreas Fault, which runs right through the Carrizo grasslands.

♪ [Hooting] Unlike in human homes, a collapsed wall from the shaking Earth is no big deal here.

Just another dirty job.

As the sun goes down, the drylands awake... and an intrepid biologist goes to work.

His groundbreaking technology shows the inner workings and interdependence of an entire community.

[Animal sounds] It is a hidden world, full of sound and scent-- alive to them, blind to us.

♪ Time for the elusive architect of Hotel California to make its debut-- the kangaroo rat, which is neither kangaroo nor rat, though it is remarkably industrious.

[Owl hooting] [Whispering] So this is our set-up for night filming here in the desert.

We've got a FLIR thermal imaging night camera, really helps us find animals.

Then over here is an infrared set-up.

It's got 2 infrared lights.

They're very powerful.

But we don't see them.

Animals don't see them.

So we're watching kangaroo rats right now.

They made a lot of the tunnels out here.

And there's one--very busy-- digging away one right now.

[Animal sounds] Narrator: Romanov's camera reveals things even the animals are unaware of.

[Owl hooting] The badger doesn't see the kangaroo rat... allowing the prey to slip away.

The rat's territory is a matter of a few hundred feet, and it fights to defend its turf from intruders.

Thumping its foot, it warns others to keep out.

♪ Truly, the tunnel-digging kangaroo rat is an excellent host, offering room, board, and a floor show at the Hotel California.

♪ Even a rattler cannot faze the pugnacious rodent.

♪ Its massive hind legs can hurl the kangaroo rat 9 feet into the air-- the equivalent of a human leaping over 100 feet.

♪ Ringing the Central Valley grasslands is one of California's dominant habitats--the oak woodlands, a transition zone between the drylands and the highlands.

Though turkeys are recent immigrants, they thrive here.

They feed on the ground, but wild turkeys can fly high and fast in short bursts.

♪ [Loud gobbling] A warning cry heralds a longtime resident, the black bear.

A clever omnivore, it's not interested in the birds.

It has come to poach acorns stowed away by acorn woodpeckers.

♪ But the real prize is high in the oak trees-- fresh acorns.

They climb for calories.

♪ [Crunching] ♪ It's a startling sight, bears in the air, but they will often spend the entire day up in the branches.

♪ In the dry season, times are tough, but a change in the wind signals that the days of plenty are just around the corner.

♪ [Growls] ♪ Every few years along the equator in the eastern Pacific, trade winds weaken, causing the waters to warm.

Lifting moisture into the air, the heated water disrupts the jet stream, impacting the weather throughout America.

El Nino, as the event is known, can last for months, and in California, it means rain-- torrential, mud-making, car-stopping rain.

For humans, it can spell disaster.

In the oak woodlands, it brings relief.

[Chirping] ♪ Now is the time of revival.

[Birds chirping] The trees put out new growth.

Sinuous lace lichen turns a light green, beckoning to woodland inhabitants who feed on it and use it for nests.

[Woodpecker pecking] The nuts stored away by the acorn woodpecker are in sudden demand, too.

[Chirping] Hungry chicks clamor for food... lots of food.

It never seems to be enough.

[Chirping continues] Ground-up acorns, newly hatched bugs, even oak flowers.

Luckily, the woodpecker raises its chicks cooperatively, with many breeding pairs using the same tree cavity.

♪ As El Nino sweeps over the dry grasslands, long dormant seeds awaken.

♪ Young badgers witness a world transformed by nascent blossoms and fragrant fields.

♪ [Beez buzzing] A desiccated lake bed fills with blossoms, an echo of the water that once filled it.

♪ The ephemeral flowers summon tourists by the thousands.

♪ And about once a decade, a super bloom occurs that is so massive, it can be seen from space.

♪ California's winemakers are glad for the rain... ♪ as is their nemesis, the pocket gopher.

♪ Grapevine roots, fresh grasses, and wildflowers are a boon for rodents.

♪ A capable engineer, the pocket gopher digs elaborate tunnels, emerging to feast on the new bounty.

♪ But coming up for air and food is hazardous.

♪ [Loud squeaking] Despite its small size, the bobcat is a spitfire.

♪ Staking out the entrance to a tunnel, the coyote is a champion of the waiting game.

♪ Predators must also be alert to subtle vibrations underground.

♪ The heron is quick on the draw.

♪ El Nino is less kind to the California Current.

Here, the super-heated weather pattern disrupts the flow of cold, nutrient-rich waters, creating a food desert in many places.

♪ The great opportunist, the coyote, scavenges fish washed ashore... ♪ while the great white shark, who hasn't fed for weeks, nears Baja California and a seal mecca.

♪ 1,000 miles south of Big Sur, seals gather in another breeding ground.

[Vocalizing] A massive bull elephant seal patrols the rocky shallows.

But these southern waters of the California Current are also the traditional hunting grounds of the great white shark.

♪ As big as he is, the seal's no match for the shark.

♪ His only option is to stay put and hope he can wait them out.

♪ The seal's strategy pays off.

The shark heads to deeper water, where it has the advantage.

♪ ♪ A baited line seems like trouble... ♪ for the shark or the fishermen.

But this is a benevolent encounter-- no hooks, no killing.

♪ ♪ Sport divers and thrill-seekers come from around the world, just for a chance to see a great white up close.

♪ While some question the ethics of baiting wildlife as a tourist attraction, others see such opportunities as a solution to the very real need for locals to make a living.

♪ On the southern tip of Baja California, a bold experiment is yielding amazing results.

In select areas, the fishing community has ceased all commercial fishing.

Instead, their towns are turning to ecotourism, and reefs are returning to their natural state.

Champion free-diver and marine biologist Estrella Navarro grew up here.

♪ She understands how this new approach can change our relationship to wild spaces.

♪ Navarro: It is a really a place to take care of, to enjoy.

This place is precious and wonderful.

I've been coming here for years now.

Narrator: Just in Navarro's lifetime, these watery Edens have been transformed.

♪ Once a desolation of overfishing, they now explode with life... ♪ giving us a glimpse of what all wild places could look like if given a chance to recover.

♪ The interplay between diverse species, each depending on and benefiting from the other, is a blueprint for balance.

♪ Navarro: There are sea lions that know me, and they play with me as soon as I arrive.

♪ They were spinning, dancing with me, jumping.

Super happy.

Following me!

Ha!

And they like to be closer to you.

♪ It's really like a sensation that fills your heart.

No?

It's beautiful.

♪ Narrator: If we can make room for them, there may still be room for us.

♪ ♪ To order "Planet California" on DVD, visit ShopPBS or call 1-800-PLAY-PBS.

This program is also available on Amazon Prime Video.

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